1. Field of the Invention
This invention relates generally to developing accurate 3-D diagnostic medical ultrasound volume data from information acquired from scanning a human or animal body with a 1-D ultrasound transducer.
2. Description of the Prior Art
There are several methods in the prior art for gathering 3-D ultrasound volume data using a 1-D ultrasound transducer. These methods typically involve moving a 1-D ultrasound transducer with a linear array of elements over the surface of the 3-D volume in the elevation direction (perpendicular to both the long axis of the linear array and the vertical direction into or out of the surface being scanned). A 3-D volume is generated, based on assuming a particular motion of the transducer. As a result, the 3-D volume is qualitative rather than quantitative, making the data inadequate for measurement of various parameters such as distances, areas, and volumes.
There are also several quantitative methods in the prior art as well. Some prior art methods use mechanical position sensors to detect the relative positions of the 1-D ultrasound transducer. Other prior art methods use a magnetic position sensor or a precision motor to move the transducer along the elevation direction by precise translational increments to achieve the same objective. The position sensing methods require additional hardware, making the ultrasound transducer more specialized, unwieldy, and costly.
The prior art also discloses using a variety of parameters (e.g., timing delay, spectral breadth, spectral power and the speckle de-correlation coefficient) to estimate the elevation motion of a 1-D ultrasound transducer without using additional hardware. While this method is less costly and simpler to use, the accuracy of position estimation of the transducer may not be adequate for quantitative measurements due to limitations inherent in the methods, such as direction ambiguity due to symmetric correlation functions.
A method has been disclosed for generating a spatially accurate 3-D data set from a series of 2-D data sets from an ultrasound transducer modified to incorporate multiple arrays. This method is described in co-pending U.S. patent application Ser. No. 08/916,585, filed on Aug. 22, 1997, entitled "Multiple Ultrasound Image Registration System, Method and Transducer," which is assigned to the assignee of the present invention.
What is needed is a method for generating a spatially accurate 3-D ultrasound data set using a 1-D single array ultrasound transducer without any modifications or the addition of position sensing hardware.